Pressure compensating register for gas meters



.' May 17, 1938. A. D. MacLEAN 2,117,341

PRESSURE COMPENSATING REGISTER FOR GAS METERS Original Filed June 21, 1930 2 Sheets-Sheet l INVENTOR.

rUie/v D/llaclan ATTORN E YJ May 17, 1938.- A. D. M cLEAN 2,117,341

PRESSURE COMPENSATING REGISTER FOR GAS METERS Original Filed June 21, 1930 2 Sheets-Sheet 2 IN VENTOR. fil/e/v 0. P7006900.

BY KW? M2 .4 ORNH YJ Patented May 17, 1938 2,117,341

UNITED STATES PATENT OFFICE PRESSURE COMPEN SATING REGISTER FOR GAS IIETERS Allen D. MacLean, Pittsburgh, Pa., assignor to Pittsburgh Equitable Meter Company, Pittsburgh, Pa., a corporation of Pennsylvania Original application June 21, 1930, Serial No. 462,843. Divided and this application July 2, 1934, Serial No. 733,522

16 Claims. (Cl. 73233) This invention relates to an improved mechregistered on the chart. Thus the volume of gas anism for directly indicating accurately the total is registered by the gas meter and the pressures flow of gases in spite of variations in the pressure thereof may be read from the pressure chart and a of such gases during the period over which the series of calculations may be made for set inindication is given. This application is a divitervals of time, for example, for each half hour, sion of the application of Allen D. MacLean and or by volume increments to thus secure an ap- Fritz Niesemann Serial No. 462.843 filed June 21, proximately correct calculation of the volume of 1930, for Pressure compensating gas meter. gas at an unvarying or base pressure. Obviously As is well known, the usual type of gas meter either of the above methods are laborious and registers the volume of flow of gas passing theretime consuming and liable to human error in 10 through without taking into account or comcalculating the corrected volume of gas.

pensating for the fact that a much greater It is an object of this invention therefore, to

quantity of gas by weight passes through the provide a measuring system and apparatus for use meter when the pressure on the line is increased. with gas lines in which the corrected volume of lo When gas is sold to large users thereof, such as gas as reduced to a predetermined base pressure industrial plants. the contract between the gas may be read directly from the meter without comcompany and the user usually designates the putations.

price of a unit volume of gas at a predetermined Another object of this invention is to provide a pressure, such as four ounces pressure for excompensating gas meter of the above indicated ample. Since the gas is a compressible medium type in which the parts are compactly arranged 20 the quantity passing through a meter is dependin a single instrument and in which the volume of out not only upon the volume, but also upon the gas passing through the meter is automatically pressure in accordance with Boyles law. In registered at a predetermined base pressure irremost installations it is impractical for the gas spective of fluctuations in pressure in the gas 5 company to constantly maintain a definite presline. 5 sure at all times, and frequently it is not feasible Another object of this invention is to provide a to keep as low a pressure as four ounces 0n the compensating or direct reading gas meter of the main, since the fluctuating demands of the conabove indicated character embodying mechanism sumers require a much higher pressure at peak whereby the meter may be readily changed to times. Quite frequently gas companies maintain compensate for different base pressures of the gas. 31) variable pressures in their line under such con- Another object of this invention is to provide a ditions and obviously the total quantity of gas by compensating gas meter of the above indicated weight, or the B. t. u. content of a specified character having associated therewith a chart volume is much greater at these higher pressures upon which is recorded the actual pressures of 35 than at the lower pressures, so that ordinary gases and having acorrected volume register and 35 meters give no correct indication of the total an uncorrected volume register, whereby the quantity of gas that has passed therethrough. accuracy of the corrected register may be checked In order to assure a correct charge to the con by the old method of calculating the pressure and sumer for the actual amount of gas used, various the uncorrected volume, and whereby the pressure expedients have heretofore been resorted to by variations in the line are automatically recorded 40 gas companies. In some installations Pitot tubes for further reference. have been used, or an orifice meter is positioned Still another object of this invention is to proin the gas conduit and combined with charts on vide a compensating gas met-er including a cor separate dials to record the differential or dyrected volume register in combination with a namic pressures for a given period of time, and record chart upon which is recorded the actual 45 then obtain separately the average static prespressure of the gas and time increments of sures for the same period, after which the volume volume.

of gas as reduced to a definite base pressure is These and various other objects of our invencalculated according to the known constant for tion will be apparent from the following descripthe orifice or Pitot tube meter. In other installation and the appended claims when taken in contions, the usual displacement type gas meter neciion with the accompanying-drawings, wherehas been provided with a chart driven either by in:

clockwork, or by movement of the meter itself, Figure 1 is a partly diagrammatic front view this chart being connected with a static pressure with parts broken away of an embodiment of my gauge such that the static pressure of the gas is invention applied to a positive gas meter, the

cycling structure being near the end of its upstroke.

Figure 2 is a detail of the ratchet throw-out mechanism of Figure 1, the mechanism being on its down stroke.

Figure 3 is a section on line III-III of Figure 2, the mechanism being at the bottom of its stroke.

Figure 4 shows a modification similar to Figure 1 in which the chart is driven by a clock. I

Figure is a fragmentary view in elevation showing the parts in the position illustrated by Figure 3.

Referring to Figures 1 and 2 of the drawings wherein is illustrated one embodiment of my improved meter, there is provided a vertical shaft 2a having an arm 3 on the lower end thereof within a casing I adapted for driving engagement with a rotating crank 3a of a positive gas meter Ia. The shaft 2, which is driven from shaft 2a by suitable gearing, has a crown gear 4 thereon, for engagement with the gear 6 connected directly to a volume register or counter 1, whereby the register 1 will register the volume of gas passing through said meter without regard to the variations in pressure of said gas. The shaft 2 extends upwardly beyond the crown gear 4 and has secured on the upper end thereof a cam member 86. Cam member 86 is provided with a vertically extending cam surface which progressively changes from a low portion to a high portion with a substantially vertical step connecting the highest and lowest portions.

A suitably guided reciprocating shaft 81 having a roller 88 on the lower end thereof is provided, the roller 88 being adapted for contacting engagement with the surface of .the cam 86 to thereby reciprocate the shaft 81 vertically as the shaft 2 revolves. The shaft 81'has a spring pressed pawl 89 on the upper end thereof for engagement with the milled edge of a disc 9| having a chart secured thereto whereby the disc 9I is driven in one direction only.

Adjacent its lower end the shaft 81 is provided with a pin 92 which projects'into slot 93 of a pivoted and oscillatable lever 94. Lever 94 is pivoted at 94 and has secured, adjacent the other end, a spring 95 for normally maintaining the lever inits lowest position. The upright bar or bracket 96 which together with lever 94 constitutes a cycling means, is guided for vertical movement and for slight lateral movement in a swivel or pivoted bearing 91, and has a projecting pin 95', and lever 94 bears against this pin on its upward cycle of movement. The bar 96 carries fine rack teeth 98 for engagement with the milled edge of a gear I9I which drives the compensated register or counter I05. Gear I9I drives a crown gear I92 for meshing engagement with a corresponding gear I93 mounted on the shaft I94 of the compensated register I95.

The bar 96 is secured at its upper end to a reciprocatory block I99 upon which is pivoted a member I91 having a locking shoulder I98 thereon. Member I91 has secured thereto an arm III, and is connected to a spring H2 which normally tends to rotate the member I91 in a clockwise direction.

The outer end of the arm III is positioned for rubbing engagement with an arm H4 of a stationary adjustable guide block H5 having at its upper end a threaded stud HE. A shoulder H9 is provided at the connection of arm H4 to block H5, and as the arm III reciprocates with the block 196 in contact with arm H4, this shoulder is engaged by arm III and limits the upward movement of its outer end. The threaded stud II 6 passes through a stationary supporting bracket H1 and isprovided with two lock nuts H8 on oposite sides of bracket H1, whereby the shoulder H9 may be adjusted to adjust the point at which it is engaged by arm HI as it moves upwardly. A spring I2I slidably engages the block I96 and tends to maintain the block I96 against guide block H5 and the rack teeth 98 on the bar 96 in engagement with the milled edge of the rotary member IIlI on the upstroke of the bar 96, the block H5 and spring I2I serving as a guide for the bar. I

From the structure as thus far described it will be seen that when the lever 94 and the bar 96 are moved upwardly by rotating cam 86 due to the passage of an increment of volume of gas through the meter, the rack teeth 98 engage the milled edge of member IOI to cause rotation of the compensated register I95. When the bar 96 approaches near the uppermost limit of its movement the end of pivoted arm III engages the shoulder H9, and further upward movement of the bar 96 causes rotation of arm III about the pivotal juncture of arm III with shoulder I I9 whereby the block I96 and rack 98 are moved to the left against the action of spring I2I, thus causing the rack teeth 98 on the bar 96 to be disengaged from the milled edge of the rotary member IIlI, so that for the remainder of the upward cycle of bar 96 the corrected register I95 is not operated. When the roller 88 leaves the high portion of the cam 86 due to rotation of the cam the spring 95 then at once returns the lever 94 to the lowest position, and the spring I21 causes the bar 96 to follow.

A proportional spiral cam I22 is mounted adjacent the lower end of the bar 96 and said cam is connected to a pressure coil I22 of any suitable type to be operated in accordance with the static pressure of gas in the conduit. The cam I22 may be rotated by a mechanism similar to that disclosed in Figures 1 to 5 of said application Serial No. 462,843 of MacLean and Niesemann, or said cam may be mounted directly on the shaft of a pressure coil. As seen in Figure 1, the cam I22 provides an adjustable stop against which the spring I21 moves the bar 96 and rod I25 when the cam 86 allows the spring 95 to return the lever 94 to initial position. This cam or stop -is variably positioned in accordance with the pressure of gas in the conduit, and as lever 94 is not fixed to bar 96, the operative movement of the reciprocating bar 96 is governed. in accordance with the static pressure of the gas.

In order to maintain the rack teeth 98 out of engagement with'the rotary member I9I when the mechanism is returning to its pressure controlled lower position I have provided a locking dog I23 pivoted on the block I96 and provided with a locking shoulder I24 for cooperative engagement with the locking tooth I98 of the member I91, which maintains arm III in locked'position and thereby keeps rack teeth 98 out of engagement with the milled edge IUI on the downward stroke of bar 96. The locking dog I23 has pivotally connected thereto a downwardly extending rod I 25 the lower end of which is adapted to engage on the surface of the cam I22. The rod I25 has secured thereto a ring or shoulder I26, the upper surface of which is engaged by a coil spring I21,'the opposite end of the spring engaging the bearing 91 to thus maintain the rod I25 in its lowermost position and tending to return bar 96 to its pressure controlled position.

In order to record the pressure for each increment of volume of gas on the chart driven by member 9| I have provided a registering pen I28 pivoted at I29 and having a slot I3l therein through which projects a pin I32 carried on the block I06. It will thus be seen that the recording arm I28 will record on the chart each oscillation of the movable mechanism. Since the length of each oscillation of the movable mechanism including the block I06 is dependent upon the position of the cam I22 which is governed by the pressure, it will be obvious that the length of the line recorded by the indicating pen I28 will show the actual pressure of gas for each increment of volume.

The operation of this embodiment of the invention is as follows: For each rotation of the shaft 2, the pivoted lever 94 moves through one cycle of operation, the cam forcing said arm upwardly against tension of the spring 95. Due to the spring I2I the rack teeth on the bar 96 are normally engaged with the rotary member IOI, whereby upward movement of the mechanism causes the register I05 to be operated. When the arm III engages the shoulder H9, the block I06 and the bar 96 are pivoted to the left against tension of spring I2I to disengage the rack teeth 98 from the rotary member IOI. Further upward movement of the pivoted lever 99 and bar 96 will have no effect on the register I05 since these parts are disconnected.

The locking shoulder I24 on the pivoted dog I23 engages tooth I08 of the rotary member I01, when said member I01 has rotated to the position shown in Figure 1 to maintain disengagement of the rack 98 from the member IOI. When the roller 88 leaves the high portion of the cam 86, the spring 95 at once draws the pivoted lever 94 downwardly, and spring I21 moves bar 96 and block I06downwardly. The rod I25 projects beyond the lower end of the bar 96 such that this rod is the first to engage the variable stop I22. When this engagement occurs the rod I25 is raised against tension of the spring I21 to lift the locking dog I23 out of engagement with member I01, Figure 5 whereby the spring I2I may reengage the rack 98 with the rotary member IOI, the lower end of the bar 96 engaging the variable stop I22 to determine the lower limit of movement for the rack. Since the cam I22 is variably positioned in accordance with the static pressures of gas it will be apparent that the operative throw of the reciprocating mechanism is dependent upon the gas pressure.

The arrangement is such that when the actual or static pressure in the conduit equals the base pressure to which the instrument is set, the cam I22 will have its high portion positioned for engagement by the bar I25 and the bar 96. Due to these conditions the throw of the mechanism is at a minimum and the register I05 will register the same as the register I. As the pressure increases the cam I22 turns to position lower portions thereof in the path of the movable mechanism, whereby the operative throw of bar 96 will be increased to thereby register higher on the register I05.

It will thus be seen that this embodiment of my invention illustrates a mechanism wherein a reciprocatory member whose movements are in accordance with the volume flow of gas is restricted in its cycle of movement by the static pressure of the gas, the mechanism being so arranged that the compensated register is moved during a portion of the complete throw of said reciprocatory member depending upon gas pressure. It will be understood that when the pressures are low the cam I22 will support the pivoted arm 94 and the roller 88 out of engagement with the cam face 86 during a portion of movement of said cam member. The pressure indicating arm I28 will register on the movable chart the oscillations of the block I06, the length of said oscillations being in accordance with the static pressure of the gas.

The adjustable stop II5 with the shoulder H9 is positioned for adjustment to provide for registration of the mechanism at base pressures. It will be understood that the position of the shoulder H9 governs the period of engagement between the rack teeth 98 and the operating register I05. By adjusting the shoulder II9 vertically, the operative throw of the movable mechanism may be regulated in a simple manner to cause the two registers I and I05 to register the same when the static pressure equals the base pressure for which the instrument is designed.

It will be understood that the cam I22 is detachably associated with the pressure gauge by any well known expedient, for example, a set screw for the substitution of other cams, each cam being designed for a particular pressure range.

In the modification shown in Figure 4. corresponding parts are numbered alike. In this modification the chart 9Ia is driven by a time train or clockwork, and the indicating arm I28 registers thereon the static pressure of the gas by the radial length of the lines recorded; and increments of volume of gas by the circumferential spacing of the recorded lines since the number of oscillations per period of time will clearly show the speed of rotation of the shaft 2 which is driven by the volume flow of the gas. Also in this modification shaft 81a which carries the roller 88 is not extended, and lever 94a which is pivoted at 94' and has the slot 93a therein and is pivotally connected at I35 to the upright bar 96, said bar being guided for vertical movement and for slight lateral oscillatory movement in the bearing 91a. The bar 98 has a lateral clearance in the bearing 91a as indicated at 91'. The cam 86 is so located that the follower 88 does not necessarily descend at all times to the face of the cam.

It will be seen from a consideration of the above that I have provided an accurate and readily adjustable gas meter which is comparatively appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What I claim and desire to secure by United States Letters Patent is:

1. In a register, a shaft adapted to be driven by a meter, an oscillatory lever, cam means on said shaft for moving said lever in one direction,

registering means, register driving means operable by oscillations of said lever for operating said registering means, pressure means responsive to the pressure effective on said meter, means independent of said pressure responsive means for disconnecting said register driving means from said registering means at one point in the movement of said lever, a spring to move the lever in the opposite direction, and means variably positioned by said pressure responsive means in accordance with said pressure for causingreengagement of said register driving means and said registering means.

2. In a volumetric gas meter of the type wherein the volume flow of gas is registered as reduced to a predetermined base pressure, a register; reciprocatory means; means to drive said reciprocatory means in response to a predetermined increment of uncorrected volume flow of gas through the meter; means whereby said reciprocatory means normally operates said register; mechanism for disconnecting said register operating means from the register upon passage of the predetermined increment of uncorrected volume flow of gas through the meter; pressure responsive means responsive to line pressure; a stop positioned by said pressure responsive means to be engaged by said reciprocatory means, said stop governing the throw of said reciprocatory means; and means releasable by said stop for maintaining disengagement of the reciprocatory means and the register.

3. In a mechanism adapted for connection to a volumetric gas meter, a register; means to drive said register to indicate the volume of gas passing through said meter; a second register; pressure responsive means; a chart; means including said pressure responsive means for recording on said chart the static pressures of gas; and means operatively connected to said first mentioned register controlled by said pressure responsive means for driving said second register to increase the readings thereof in accordance with pressure variations to indicate the volume of gas passing through the meter reduced to a predetermined lower base pressure.

4. In a mechanism adapted for connection to a volumetric gas meter; a register; means to drive said register at a rate proportional to the volume of gas passing through said meter under supply pressure; a second register; and means to drive said second register to increase the reading thereof in accordance with supply pressure variation to indicate the volume of gas passing through said meter reduced to a predetermined base pressure, said drive means comprising solely mechanical means including cam means and pressure responsive means to control said solely mechanical means in accordance with supply pressure; a chart; means for driving said chart by said meter at a rate in accordance with the volume flow of gas; and means including said pressure responsive means for recording on said chart the supply pressures of the gas, said chart drive means and said recording means cooperating to record simultaneously pressures affecting said second register drive means.

5. In a volumetric gas meter, a register; and means for driving said register in accordance with the volume fiow of gas through said meter so that the register will register the volume of gas as reduced to a predetermined base pressure, comprising a shaft driven by the volumetric gas meter, a driving connection between said shaft and said register, and means including a cam member and a static pressure responsive element for causing said driving connection to drive said register at a rate varied automatically in accordance with the pressure of the gas, and a chart, means for driving said chart by said meter at a rate in accordance with the volume flow of. gas and means including said pressure responsive element for recording on said chart the supply pressures of gas.

6. A volumetric gas meter comprising a register and means to drive said register to indicate the volume flow of gas through the meter; a second register; driving means for said second register operatively connected to the driving means of said first named register; said drive means for said second register comprising a cam mechanism and a clutch, and pressure responsive means connected for response to supply pressure to control said cam mechanism to drive said second register by said clutch at a rate varied in accordance with pressure variations to correct the indication of said second register to a predetermined lower base pressure, a chart, means to move said chart and a pressure operated pen actuated by said pressure responsive means for producing a record of pressures on said chart.

7. In a volumetric gas meter, a register; and means for driving said register in accordance with the volume flow of gas through said meter so that the register will register the volume of gas as reduced to a predetermined base pressure, comprising a shaft driven by the volumetric gas meter, a driving connection between said shaft and said register, and means including a cam member and a static pressure responsive element for causing said driving connection to drive said register at a rate varied automatically in accordance with the pressure of the gas, a chart, means for driving said chart at a constant rate, and a recording pen periodically actuated by said driving connection to record on said chart increments of corrected volume.

8. In a register, a shaft adapted to be driven by a meter, an oscillatory member, means for biasing said member in one direction, cam means operated by said shaft for moving said member against the bias, register means. reciprocable register driving means for operating said register means adapted to be reciprocated by said oscillatory member, said reciprocable means adapted to drive said register means when moving in one direction only, means for disengaging said rcciprocable means from said register means at a point in its drive movement, pressure responsive means, and a stop variably positioned by said pressure responsive means for reengaging said reciprocable means and register means.

9. In a register, a shaft adapted to be driven by a meter, an oscillatory lever, cam means on said shaft for moving said lever in one direction, registering means, register driving means operable by oscillations of said lever for operating said registering means, a stationary stop, a member operatively connected to said register driving means engageable with said stationary stop and operable by oscillations of said lever for moving said driving means transverse to its normal path of movement to disconnect said register driving means from said registering means, a spring to move the lever in the opposite direction, pressure means responsive to the pressure effective on said meter, and means variably positioned by said pressure responsive means in accordance with said pressure for causing reengagement of said register driving means and said registering means.

10. In a register, a shaft adapted to be driven by a meter, an oscillatory lever, cam means on said shaft for .moving said lever in one direction, registering means, register driving means operable by oscillations of said lever for operating said registering means, means for disconnecting said register driving means from said registering means at one point in the movement of said lever, latch means for locking said register driving means in disconnected position, a spring to move the lever in the opposite direction, pressure means responsive to the pressure effective on said meter, and means variably positioned by said pressure responsive means in accordance with said pressure for disengaging said latch means and causing reengagement of said register driving means and said registering means.

11. In a volumetric gas meter for indicating the volume flow of gas passed therethrough reduced to a predetermined base pressure, a shaft driven by said meter, an oscillatory member, means driven from said shaft for moving said member in one direction and yieldingly returning said member to its original position, a counter, means operable upon positive movement of said member for operating said counter, pressure actuated means for determining the period of operativeness of the counter operating means, a chart, means for rotating said chart, and visible recording means controlled by pressure changes and actuated from said oscillatory member for producing a record of gas volume and pressure on said chart.

12. In a volumetric gas meter for indicating the volume flow of gas passed therethrough reduced to a predetermined base-pressure, a shaft driven by said meter, an oscillatory member, cam means driven by said shaft for moving said member in one direction, means for yieldably returning said member in the opposite direction, registering means, register driving means engaged upon movement of said member in one direction for operating said registering means, means effective at a predetermined point in such movement for disengaging the register driving means from the registering means, and pressure actuated means for determining the amount of movement of the register driving means.

13. In a volumetric gas meter for indicating the volume flow of gas passed therethrou'gh reduced to a predetermined base pressure, a shaft driven by said meter, a corrected pressure counter having a gear, an oscillatable member, cam means driven from'said shaft for moving said member in one direction, a drive gear rendered operable upon movement of said member in said one direction for driving the corrected pressure counter gear, means for removing said drive gear from contact with the corrected counter gear and pressure actuated means effective upon said member for determining the amount of movement of said member.

14. In a register, a shaft adapted to be driven by a meter, an oscillatory lever, cam means on said shaft for moving said lever in one direction, registering means, reciprocable means adapted to be reciprocated by said lever, said reciprocable means being adapted to drive said registering means when moving in one direction only, means for disconnecting said reciprocable means from said registering means at one point in the movement of said reciprocable means in said one direction, a spring to move said lever in the opposite direction, pressure responsive means responsive to the pressure effective on said meter, and means variably positioned by said pressure responsive means in accordance with said pressure for causing reengagement of said reciprocable means and said registering means.

15. In a register having a pressure responsive element and a shaft adapted to be driven by a meter, registering means provided with a gear, register driving means, a shiftable bar serving as a part of the register driving means, toothed means on said bar and said bar being shiftable to engage or disengage said gear and toothed means, cam means on said shaft to effect movement of said bar, a control arm operatively connected to said bar at a portion removed from said toothed means, and a member variably positioned by said pressure responsive element and adapted to engage said control arm for effecting bodily movement of said whole bar to place said toothed means in engagement with said gear.

16. In a register having a pressure responsive element and a shaft adapted to be driven by a meter, a pressure corrected counter having a gear, a movably mounted member, cam means driven by said shaft for effecting movement of said member in one direction only, said member being normally urged in the opposite direction, toothed means on said member adapted to engage said gear only when said member is moved in said one direction, and means controlled by said pressure responsive element for determining the amount of contact between said gear and said toothed means.

ALLEN D. MACLEAN. 

